NC: Behavior Change Strategies (2007-2008)
- To compare two different extended treat interventions (relapse prevention therapy and problem solving) with standard behavior therapy
- To determine whether there was a relative advantage of intensive didactic training in a comprehensive range of relapse prevention skills, compared with continued professional assistance in the form of therapist-led group problem-solving.
- Age: 21 to 60 years
- BMI: 27 to 40
- Good health
- Physician's approval to participate in a diet and exercise weight-loss intervention.
- Recruitment: Participants recruited from newspaper advertisements and screened for eligibility.
- Design: Randomized controlled trial.
- All participants received the same initial cognitve-behavioral weight-loss intervention
- Weekly two-hour group sessions with 11 to 14 members per group, for 20 weeks
- Three groups:
- Behavior Therapy (BT): Two groups
- Relapse Prevention Therapy (RPT): Three groups
- Problem-Solving Therapy (PST): Three groups.
- Standard behavioral weight-management techniques taught in a didactic fasion: Self-monitoring, goal-setting, stimuls control, etc.
- Instructed to follow 1,200kcal (1,200 per day for women), low-fat diet (25% of total kcal per day)
- Home-based walking program of 30 minutes per day, five days per week
- Conducted by pairs of clinical psychology graduate students, who adhered to a written protocol.
- During year after initial treatment
- Behavior Therapy
- Relapse Prevention Therapy
- Problem-Solving Therapy.
- Analysis of variance (ANOVA) for comparisons of groups
- Multi-variate ANOVA (MANOVA) for comparisons of multiple variable between groups
Timing of Measurements
- Weight, eating and exercise diaries: Weekly for 20 weeks
- BT: Weight; six and 12 months
- RPT and PST: Weight, eating and exercise diaries; bi-weekly for one year.
- Body weight: Scale (type and calibration not specified)
- Adherence: Self-reported for nine behavioral weight-management strategies (Likert scale; 1=non-adherence and 7=full adherence).
BT, RPT or PST.
103 (gender not specified).
Attrition (Final N)
- Completion of initial behavioral treatment
- N=88; 80 females and eight males, 85%
- 80 females included in analysis, eight males excluded because they were unequally distributed between groups.
- Completion of extended therapy (dropouts were those who withdrew voluntarily or attended fewer than two sessions during Months 12 to 17)
- RPT: 29%
- PST: 34%.
- Final assessment (weight)
- BT: 83%
- RPT: 71%
- PST: 66%.
Final sample: Mean (SD)
- BT (N=18): 45.23 (10.08) years
- RPT (N=28): 49.17 (7.21) years
- PST (N=34): 45.36 (9.33) years.
Other Relevant Demographics
- BT: 13.13 (1.93) years
- RPT: 14.00 (1.63) years
- PST: 14.50 (2.06) years.
- Height (m)
- BT: 1.62 (0.06)
- RPT: 1.66 (0.06)
- PST: 1.65 (0.06).
- Weight (kg)
- BT: 94.67 (11.35)
- RPT: 96.95 (13.69)
- PST: 97.96 (16.01).
- Body mass index (BMI; kg/m2)
- BT: 36.37 (4.70)
- RPT: 35.00 (3.96)
- PST: 36.10 (4.93).
- Completers (N=58) vs. non-completers (i.e., dropped out or did not complete final assessment; N=22)
- Attendance during initial treatment was equivalent
- Completers: 86%
- Non-completers: 93%
- Attendance during extended treatment was poorer for non-completers
- Completers: 73%
- Non-completers: 33%
- Non-completers had higher initial body weights than completers: 103.2kg vs. 94.4kg; P=0.012
- Non-completers had non-significatly smaller reductions in percentage of body weight during initial treatment than completers: 10% vs. 8%; P=0.163.
Mean Net Weight (kg) Changes [Mean (SD)] by Conditions Over Time for Completers
|Time Period||BT (N=15)||RPT (N=20)||PST (N=23)|
|Baseline to Month 5||
|Month 5 to Month 11||
|Month 11 to Month 17||
|Baseline to Month 17||
Classification of Participants According to Categories of Change in Body Weight (Percentage) From Baseline to Final Follow-Up
|Category of Change||BT||RPT||PST|
|Lost 10.0% or greater||
|Lost 5.0% to 9.9%||
|Lost 0.0% to 4.9%||
- A larger percentage of PST participants achieved a clinically significant loss of more than 10% body weight than did BT participants (P=0.025)
- Differences between the RPT and BT and between PST and RPT were not significant.
Mean (SD) Adherence Scores for Completers by Condition at Months Five, 11 and 17
|Assessment Point||BT (N=15)||RPT (N=20)||PST (N=23)|
- PST group demonstrated significantly better adherence to behavioral weight management strategies than the BT group from Months Five to 11 (P=0.043) and from Months 11 to 17 (P=0.041).
- The effect of treatment condition on weight loss was significant (P=0.01)
- When analyzed with adherence entered, the results showed a significant effect for conditions (P=0.059). Amount of variance accoudnted for by adherence: R2=0.72.
- An extended treatment intervention based on a problem-solving model of obesity management demonstrated significantly better weight reduction and long-term maintenance of lost weight than standard BT
- Extended professional contact alone may not be sufficient to improve long-term weight management.
|Government:||Dept. of Veterans Affairs|
Quality Criteria Checklist: Primary Research
|1.||Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)||Yes|
|2.||Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?||Yes|
|3.||Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?||Yes|
|4.||Is the intervention or procedure feasible? (NA for some epidemiological studies)||Yes|
|1.||Was the research question clearly stated?||Yes|
|1.1.||Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?||Yes|
|1.2.||Was (were) the outcome(s) [dependent variable(s)] clearly indicated?||Yes|
|1.3.||Were the target population and setting specified?||Yes|
|2.||Was the selection of study subjects/patients free from bias?||Yes|
|2.1.||Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?||Yes|
|2.2.||Were criteria applied equally to all study groups?||Yes|
|2.3.||Were health, demographics, and other characteristics of subjects described?||Yes|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||???|
|3.||Were study groups comparable?||Yes|
|3.1.||Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)||Yes|
|3.2.||Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?||Yes|
|3.3.||Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)||Yes|
|3.4.||If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?||N/A|
|3.5.||If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)||N/A|
|3.6.||If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?||N/A|
|4.||Was method of handling withdrawals described?||Yes|
|4.1.||Were follow-up methods described and the same for all groups?||Yes|
|4.2.||Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)||Yes|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||Yes|
|4.4.||Were reasons for withdrawals similar across groups?||???|
|4.5.||If diagnostic test, was decision to perform reference test not dependent on results of test under study?||N/A|
|5.||Was blinding used to prevent introduction of bias?||???|
|5.1.||In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?||???|
|5.2.||Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)||???|
|5.3.||In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?||N/A|
|5.4.||In case control study, was case definition explicit and case ascertainment not influenced by exposure status?||N/A|
|5.5.||In diagnostic study, were test results blinded to patient history and other test results?||N/A|
|6.||Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?||Yes|
|6.1.||In RCT or other intervention trial, were protocols described for all regimens studied?||Yes|
|6.2.||In observational study, were interventions, study settings, and clinicians/provider described?||N/A|
|6.3.||Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?||Yes|
|6.4.||Was the amount of exposure and, if relevant, subject/patient compliance measured?||Yes|
|6.5.||Were co-interventions (e.g., ancillary treatments, other therapies) described?||Yes|
|6.6.||Were extra or unplanned treatments described?||N/A|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||Yes|
|6.8.||In diagnostic study, were details of test administration and replication sufficient?||N/A|
|7.||Were outcomes clearly defined and the measurements valid and reliable?||Yes|
|7.1.||Were primary and secondary endpoints described and relevant to the question?||Yes|
|7.2.||Were nutrition measures appropriate to question and outcomes of concern?||Yes|
|7.3.||Was the period of follow-up long enough for important outcome(s) to occur?||Yes|
|7.4.||Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?||Yes|
|7.5.||Was the measurement of effect at an appropriate level of precision?||Yes|
|7.6.||Were other factors accounted for (measured) that could affect outcomes?||Yes|
|7.7.||Were the measurements conducted consistently across groups?||Yes|
|8.||Was the statistical analysis appropriate for the study design and type of outcome indicators?||Yes|
|8.1.||Were statistical analyses adequately described and the results reported appropriately?||Yes|
|8.2.||Were correct statistical tests used and assumptions of test not violated?||Yes|
|8.3.||Were statistics reported with levels of significance and/or confidence intervals?||Yes|
|8.4.||Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?||N/A|
|8.5.||Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?||Yes|
|8.6.||Was clinical significance as well as statistical significance reported?||Yes|
|8.7.||If negative findings, was a power calculation reported to address type 2 error?||N/A|
|9.||Are conclusions supported by results with biases and limitations taken into consideration?||Yes|
|9.1.||Is there a discussion of findings?||Yes|
|9.2.||Are biases and study limitations identified and discussed?||N/A|
|10.||Is bias due to study's funding or sponsorship unlikely?||Yes|
|10.1.||Were sources of funding and investigators' affiliations described?||Yes|
|10.2.||Was the study free from apparent conflict of interest?||Yes|